Circular stocking knitting machines may be equipped with a drawing device, which is able to take hold of the manufactured article during the manufacturing phase, tensioning it to help its downward movement inside the cylinder. Various devices, either pneumatic, or mechanical, or mixed, are already known for such a use and optionally for the turning inside out of the manufactured articles, once they are finished and discharged from the machine.
One of such devices was the object of a previous patent application of the same applicant. This device essentially comprises two tubular elements having different diameters that are inserted coaxially inside one another, are arranged on the inside of the cylinder of a circular stocking knitting machine, delimit an annular hollow space between them for the passage of the manufactured article being manufactured and form with their upper ends a gripping means for pressing the manufactured article at the entrance of said hollow space. The two tubular elements are adjustable in relation to one another for the phases of pressing and releasing the manufactured article and both together in the cylinder, when they have pressed the manufactured article, and this article must be drawn downwards during its knitting.
The prior-art devices are basically efficient but they do all display some limitation and difficulty when they are used to draw thick or bulky manufactured articles.